The Purpose of this project is to develop an electronic package using integrated circuit techniques for the transdermal delivery of complex neural stimulation patterns to an array of microelectrodes implanted in either the VIIth nerve or along the basilar membrane of the cochlea. Units capable of addressing eight- or twelve-electrode arrays will be necessary, with considerable flexibility in pulse delivery characteristics to the individual electrodes. A two channel transmission system through the skin will be used; a radio-frequency link to supply power and an ultrasonic link to deliver the stimulation instructions. The implanted unit must be small, low power, and light weight. The hardware development will be coordinated with clinical studies, initially in animals, to be conducted at the Stanford School of Medicine under the direction of F. Blair Simmons and at the University of California School of Medicine under the direction of Michael M. Merzenich.